Can i integrate?

I really need to integrate some chicks i have but not sure how to do it or what to expect if i do, do it?
The chicks i have consist of 3 silkies 13 weeks old, 4 cochin bantam 10 weeks old and i also have 2 marans who are 8 weeks old. They are currently in brooders which are inside the main coop so my older hens and pullets are used to seeing them on a daily basis.
Their brooders are getting too small for them now so really need to move them out of their brooders and in to the main coop space but i'm worried how the other girls will react.
I have a large coop which is 12x14 and they free range in a very large garden (sorry don't know the actual size) from when they are let out in the morning till they go in at dusk.
I do have an inclosed run area surrounding the coop and i did think to let the chicks use that and lock out the big girls for a week or so and only let them in so they can go to bed but the problem with that is that the girls would not have access to the nest boxes in the coop, so that is out of the question which is a shame as i think that would of worked well for a few months till the chicks got a bit bigger.
Any ideas as to how i can make this happen, while keeping every one happy and safe?

I had chicks with a broody in a chain link run with 5 other hens. The chicks could escape through the chain links and get away until they were feathered out well. Surprising how small of an opening they can squeeze through. I have also lined cinder blocks together that the chicks can run through for shelter.